Mesoscale Discussion 252

Issued

Mar 24, 2009, 5:36 PM CDT (22:36 UTC)

Expired

Mar 24, 2009, 6:30 PM CDT

In force

54 min

Issued by

the Storm Prediction Center

The Paducah radar (KPAH), 139 km from the middle of the area, began a volume at 22:40 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

000 
ACUS11 KWNS 242237
SWOMCD
SPC MCD 242236 
KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-MSZ000-242330-

MESOSCALE DISCUSSION 0252
NWS STORM PREDICTION CENTER NORMAN OK
0536 PM CDT TUE MAR 24 2009

AREAS AFFECTED...PORTIONS CENTRAL/ERN AR...SERN MO...SRN IL...WRN
KY...WRN TN.

CONCERNING...SEVERE THUNDERSTORM WATCH 60...

VALID 242236Z - 242330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 60
CONTINUES.

CONTINUE WW ALONG/AHEAD OF SQUALL LINE INITIALLY POSITIONED FROM
SERN MO SWWD ACROSS CENTRAL AR.  SOME COUNTIES E OF WW MAY NEED TO
BE ADDED AS CONVECTIVE TRENDS PERMIT...ESPECIALLY AHEAD OF NRN BOW
ACROSS PORTIONS SRN IL.  HOWEVER...SUBSTANTIAL STABILIZATION TRENDS
WITH EWD EXTENT INDICATE ATTM THAT ADDITIONAL WW MAY NOT BE NEEDED
FARTHER E.

CONVECTIVE BAND CONTAINS TWO PRIMARY BOWING SEGMENTS MOVING ENEWD
APPROXIMATELY 40 KT...ONE MOVING ENE TOWARD CGI-MDH AREA...AND ONE
NEAR ARG MOVING TOWARD NWRN TN.  SFC ANALYSIS SHOWS COLD FRONT
ACROSS N-CENTRAL THROUGH SWRN AR BEHIND THIS LINE...WITH
INSUFFICIENT TIME AND SPATIAL EXTENT FOR ADDITIONAL/FRONTAL
DEVELOPMENT BEHIND STABILIZING EFFECTS OF INITIAL CONVECTIVE BAND.
DEEP-LAYER KINEMATIC PROFILES AND LOW-LEVEL SHEAR WILL REMAIN
FAVORABLE FOR SVR...WITH 45-55 KT EFFECTIVE SHEAR MAGNITUDES EVIDENT
WHERE AT LEAST MRGL BUOYANCY EXISTS.  HOWEVER...LACK OF INSTABILITY
WILL LIMIT SVR POTENTIAL WITH ACTIVITY OVER AND DOWNSHEAR FROM THIS
AREA THROUGH REMAINDER AFTERNOON.  AIR MASS AHEAD OF LINE BECOMES
DRIER AND LESS BUOYANT EWD ACROSS MS RIVER INTO IL/TN...WITH
CONVECTION MOVING PAST EARLIER/PRE-STORM MOIST AXIS.  MOIST AXIS
STILL IS EVIDENT JUST AHEAD OF LINE ACROSS CENTRAL/SRN AR...HOWEVER
PRECURSORY CLOUD/PRECIP AREA HAS HAD LIMITED DIURNAL
DESTABILIZATION...AND POTENTIAL FOR FURTHER ORGANIZATION OF ACTIVITY
WILL BE LIMITED.  PRIND DOWNWARD REFLECTIVITY TREND OVER MOST OF AR
PORTION OF LINE WILL CONTINUE...AND NRN BOW WILL WEAKEN AFTER MOVING
OVER IL INTO MORE STABLE AIR.

..EDWARDS.. 03/24/2009

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...PAH...MEG...LSX...LZK...

LAT...LON   38079038 38168909 38048813 37278811 35518931 34589087
            34639237 35179175 35689109 36109112 36879039 37499023
            37759025 38079038

Mesoscale Discussions in Illinois, 2009Mesoscale Discussions in Arkansas, 2009Mesoscale Discussions in Missouri, 2009Every mesoscale discussion in 2009

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.